Abstract

Purpose

A review of the role of the carotenoids, lutein and zeaxanthin, and their function
in altering the pathogenesis of age-related macular degeneration (AMD).

Methods

Medline and Embase search.

Results

Recent evidence introduces the possibility that lutein and zeaxanthin, carotenoids
found in a variety of fruits and vegetables may protect against the common eye disease
of macular degeneration. This potential and the lack to slow the progression of macular
degeneration, has fueled high public interest in the health benefits of these carotenoids
and prompted their inclusion in various supplements. The body of evidence supporting
a role in this disease ranges from basic studies in experimental animals to various
other clinical and epidemiological studies. Whilst some epidemiological studies suggest
a beneficial role for carotenoids in the prevention of AMD, others are found to be
unrelated to it. Results of some clinical studies indicate that the risk for AMD is
reduced when levels of the carotenoids are elevated in the serum or diet, but this
correlation is not observed in other studies. Published data concerning the toxicity
of the carotenoids or the optimum dosage of these supplements is lacking.

Conclusion

An intake of dietary supplied nutrients rich in the carotenoids, lutein and zeaxanthin,
appears to be beneficial in protecting retinal tissues, but this is not proven. Until
scientifically sound knowledge is available we recommend for patients judged to be
at risk for AMD to: alter their diet to more dark green leafy vegetables, wear UV
protective lenses and a hat when outdoors. Future investigations on the role of nutrition,
light exposure, genetics, and combinations of photodynamic therapy with intravitreal
steroid (triamcinolone-acetonide) injections hold potential for future treatment possibilities.